The numeric value of the expression in each case is given as follows:
a) 0.
b) -1/17.
<h3>How to find the numeric value of a function?</h3>
The numeric value of an expression is found replacing each instance of the variable by it's attributed value.
In this problem, we expression is:

In item a, when x = 1 and y = 3, we have that:
[3(1) - 3]/(3^2 + 1) = 0.
In item b, when x = 1 and y = 4, we have that:
[3(1) - 4]/(4^2 + 1) = -1/17.
A similar problem, in which we find the numeric value of an expression, is given at brainly.com/question/28181015
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